Lipids are critical to healthy neurodevelopment, are variably enriched across regions of the brain, and are integral to human metabolism. Meconium, the first bowel movements of a newborn, begin accumulation in approximately the 12th week of gestation, and contains high lipid content. Thus, meconium may provide a window into the abnormal neurodevelopment that occurs in the early etiology of autism spectrum disorder. This proposal will quantify and compare the lipid content of meconium in typically developing versus neurodevelopmentally delayed children from a prospective enriched risk cohort of early events in autism spectrum disorder. To extend the relevance of the putatively identified lipid biomarkers, the structures of the biomarkers will be elucidated, and the lipid content of the samples derived from the cohort will be compared to meconium from healthy newborns as well as other biospecimens from newborns. Finally, targeted methods will be developed in suitable matrices for future validation of the biomarkers. We will conduct this research in three specific aims as follows; Aim 1. Identify unknown chromatographic features with differential abundance between ASD and controls in a prospective enriched risk cohort. Aim 2. Structurally elucidate the putative biomarkers of ASD and compare the lipid content of meconium, placenta, and cord blood. Aim 3. Develop and validate a targeted method for the quantitation of putative biomarkers of ASD.